Genetic Analysis of the North Atlantic Right Whale: Implications for Species Recovery and Conservation Actions

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Rosalind Rolland and Moira Brown, New England Aquarium

Awarded: May 2004

The North Atlantic right whale (Eubalaena glacialis)
is one of the most endangered large whales, with approximately 300 individuals
remaining.The critically endangered
status and low genetic variability exhibited in this species is thought to be
due to several centuries of intensive whaling.However, the species has shown no signs of recovery since whaling
pressures were removed through international protection measures initiated in
1935.This lack of recovery suggests
that factors other than whaling have seriously affected the recovery potential
of this species.Although some
detrimental factors are known, such as the high rate of mortality due to ship
strikes and entanglement in fishing gear, it has also been identified that the
reproductive rate is significantly lower than expected, and the factors
resulting in this reduced reproductive performance remain unknown.Due to the small number of reproductively
successful individuals in the entire species, identification of the factors
affecting reproduction requires detailed information on the reproductive
success of each individual.We propose
to provide this necessary information by combining long-term
photo-identification data with high-resolution genetic analyses to create a
family tree for the species.This
genealogy will contain all behaviorally- and genetically-identified
relationships, and thus will provide details regarding the reproductive success
of specific individuals as well as their lineages.This dataset will be used to test specific
hypotheses regarding the role of genetic factors on reproduction and species
recovery.Additionally, these data will
be made available to other researchers and managers to facilitate the
determination of the factors affecting reproduction, and therefore the recovery
potential of the species. This project offers the rare opportunity to
investigate a wild species with a level of genetic detail that is often only
available in captive breeding programs.

Of the remaining right whale population,
approximately 100 females produce an average of 11 calves per year, a rate of
reproduction that is one third of that expected in comparison to the South Atlantic right whale (Eubalaena australis).Indicators of reproductive dysfunction in
this species include a high incidence of neonatal mortality; an average
inter-birth interval that is almost twice as long as expected; and a large
percentage of adult females that have never been seen with a calf.Current initiatives to evaluate health and
reproduction include the development of assays for reproductive and stress
hormones in feces, analysis of feces for pathogenic parasites and marine
biotoxins and development of a visual health assessment technique based on
archived photographic images.Here we
propose to use genetic analyses to augment these initiatives as well as to
address the role of low levels of genetic variability on the reduced
reproductive performance of this species.

Seasonal Basque
whaling in Labrador, Canada during the 16th -
17th centuries is proposed to be responsible for the most extensive
depletion of this species.A second way
to investigate current recovery potential is by assessing ancient specimens
exhibiting pre-exploitation genetic characteristics.We propose to use genetic analysis of ancient
bones to investigate the impacts of whaling on the population size and genetic
variability of this species.Combined
with the data on reproduction, this research provides methods for
scientifically testing hypotheses concerning both the factors that resulted in
the endangered status of this species as well as the factors currently
affecting its recovery.

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